Irritable bowel syndrome (IBS), a common functional gastrointestinal disorder involving the gut-brain axis, and inflammatory bowel disease (IBD), a chronic relapsing inflammatory disorder, are both increasing in incidence and prevalence in Asia. Both have significant overlap in terms of symptoms, pathophysiology, and treatment, suggesting the possibility of IBS and IBD being a single disease entity albeit at opposite ends of the spectrum. IBS is characterized by a disordered gut-brain axis, but can develop following an enteric infection, and is associated with persistent immune activation that is also a feature of IBD. Of note, the considerable overlap of symptoms and colitis points to the possibility of IBS as a prodromal or mild subset of IBD, or IBD being pathologically related to the cause of IBS, or representing same pathophysiological spectrum of a disease.